Means for taking well cores



c. M. OLEARY 2.210.464

mums FOR TAKING WELL CORES Filed Sept. 20, 1937 2 Sheets-Sheet l i I u I{MAINE CHARZE) M OZEA'RY ATTORNEY 2 Sheets-Sheet 2 C. M. O'LEARY MEANSFOR TAKING WELL CORES Filed Sept. 20, 1937 Z w a 455 Aug. 6, 1940.

625248557 M OZEARV W/MW ATTORNEY Patented Aug. 6, 1940 UNITED STATESPATENT OFFICE 11 Claims.

This invention relates to a method and apparatus by which data isobtained relative to the formation being penetrated in drilling a well,and particularly pertains to a means for taking well cores.

In the drilling of wells, and particularly oil wells which penetrate theearth to a great depth, various devices have been provided to explorethe geological formation being penetrated and to ascertain theinclination of the formation and the declination of the wellbore. It hasalso been usual practice to obtain samples of the formation known ascores, which cores are taken from the bottom of the well bore. It is theprincipal object of the present invention to provide a method and meanswhereby cores may be taken at any point in the depth of a well bore andfrom the side wall thereof, and a record obtained to be read inconnection with the cores recovered so as to determine the declinationof the well bore and to properly orient the cores with relation tomagnetic north and to the aforesaid declination.

The present invention contemplates the provision of a core takingstructure which projects a series of core receiving elements radially ofthe longitudinal center of the drill string and the structure carriedthereby, and which device embodies a well surveying instrument by whicha record is made simultaneously with the taking of the cores to indicatethe oriented position of the cores taken, as well as the direction anddegree of deviation of the well bore from the vertical.

The invention is illustrated by way of example in the accompanyingdrawings in which:

Figure 1 is a view in elevation showing the assembled tool with whichthe invention is concerned and which tool is suspended from a drillstring and into a well.

Fig. 2 is an enlarged view showing a well surveying instrument used aspart of the present invention.

Fig. 3 is an enlarged fragmentary view in central longitudinal sectionand elevation showing the details of construction of the core takingunit of the device with the core cutting members in their retractedpositions.

Fig. 4 is a view similar to that shown in Fig. 3, indicating the corecutting elements in their projected position while obtaining a formationsample.

Fig. 5 is a view in transverse section, as seen on the line 5-5 of Fig.3, and as showing the core cutters in their retracted position.

Fig. 6 is a view in transverse section, as seen on the line G--G of Fig.4, and shows the core cutters in their projected position.

Fig. 7 is an enlarged view'through the well surveying instrument, asseen on the line 1-4 5 of Fig. 2, and discloses the means by which therecord disc is oriented with relation to the surveying instrument.

Referring more particularly to the drawings, Ill indicates a drillstring to the lower end of which a pin II is threaded. This pin carriesan operating rod l2 which supports the core taking unit 53 at the lowerend of which a magnetic type well surveying unit It is carried within anarmored casing I 5. The core taking unit comprises a barrel I6 into theupper end of which. is threaded a cylinder block l1. This cylinder blockis formed with' a central bore l8 therein to receive a piston l9 whichreciprocates within the bore I8. The piston I9 is carried at the lowerend of the operating rod l2 and moves therewith. A splined bushing 20 ismounted in the upper end of the cylinder block I! and provides .a keyedguide for the operating rod [2. At the lower end of the cylinder blockI1 is a packing washer 2] which seals the lower end of this block withrelation to the barrel l6. An extension 22 is formed as a part of thecylinder block I! and projects into the upper part of a relatively largecylinder bore 23 which is in longitudinal alignment with the cylinderbore l8. This bore receives a piston 24. The piston 24 at its lower endcarries a piston rod 25 which extends downwardly through an opening 30in the lower part of the barrel I6 and carries a set of expanding cams3|. These cams as shown particularly in Fig. 6 of the drawing are in theshape of radially disposed blades. As shown in Fig. 4 of the drawingsthese blades have downwardly and inwardly tapered edges 32 which restagainst the ends of radial core barrels 33 which barrels are formed witha core receiving bore 34 preferably undercut to receive and hold a core.The inner ends of the barrels 33, as indicated at 35 are formed with adove-tail groove 36 which extends vertically and receives the dove-tailend 21 of a blade 3|. By thisarrangement it will be evident thatvertical reciprocation of the blades 3| will act to advance the corebarrels 33 to the positions indicated in Fig. 6, and to retract them tothe positions indicated in Fig. 5. The lower end of the piston rod 25when in its lowermost position extends into a guide block 38. The guideblock 38 is threaded into the barrel l6 and its lower end is threadedinto the armored housing l5. A central threaded bore 39 of the guideblock 38 receives the upper threaded end of the casing 40 of thesurveying instrument l4. A reduced bore 4| at the upper end of the bore39 in the guide block 38 accommodates the lower end of the piston rod 25and allows a contact blade 4| to project downwardly into the casing 40of the surveying instrument to complete an electric circuit .which willbe hereinafter described.

A declination instrument is shown by way of example in Fig. 2 of thedrawings, it being understood, however, that various other types ofinstruments might be used to accomplish the same result. This instrumentcomprises the upper casing 40 which has been threaded into the bore 39and within which batteries 42 are placed. Below the upper casing 40 is adepending frame structure 43 carrying a cylinder housing 44 at its lowerend. Between casing 4|] and the housing 44 a space occurs to receive asuitable electric timing mechanism 45. This timing mechanism is includedwithin the circuit from the batteries 42 and is suitably connectedtherewith by conductors 46 and 41 which control switch elements 48 and49, yieldably held toward each other by springs 50 and between which theblade 4| may be forced to complete the circuit to the timing device.This timing device is of a type which will determine the duration of acircuit fiow to an illuminating lamp 5| which is mounted within thelower cylinder housing 44. Mounted within the housing 44 below the lampbulb 5| is a reticle ring 52 which is supported by wires 53 carried by agimbal ring 54. A suitable lens 55 is disposed above the gimbal ring 54and the bulb 5|. A suitable lens 56 is disposed below the reticle ring52. At a point beneath the lens 56 within the housing 44 is a filmholder which receives a circular film card 51. This card, asparticularly shown in Fig. '7 of the drawings, is formed with a tang 58projecting radially over its marginal edge and which tang fits within agroove 59 formed in the edge of the film holder. The film holder ispermanently set within the housing 44 so that it will not rotate. Itwill thus be evident that the film 51 will be positively set withrelation to the film holder. A threaded opening 60 is formed through themember 38 and into the upper casing 40. A set screw 6| is threaded intothe opening 60 so that the upper casing 40 will be held against rotationwith relation to the core taking unit. It will thus be seen that by thisarrangement the core barrels 33 will have a definite fixed orientedposition with relation to the card 51 so that the combined informationobtained by the readings from the film card and the arrangement of thecores taken in the barrels 33 will definitely determine the declinationof the well bore, the direction of deflection, and the relativedirection of inclination and degree of inclination of the strata in thegeological formation from which the cores are being taken. It will befurther understood that if a compass reading is also obtained upon thephotographic card 51 by interposing a compass structure between thereticle ring 52 and the photographic card 51, as generally indicated at62, complete data will be obtainable from the instrument. The point atwhich readings are taken may be determined by the length of an anchorpipe 63 which is secured to the lower end of the armored casing andrests upon the floor of the well bore. Thus by computing the desiredlength of anchor pipe required side wall cores may be taken at any pointin the length of the well. The pipe may be oriented by any reliablemethod where deviation is not desired or deviation of the hole may bedetermined and then orientation of the pipe in the hole after whichcores are taken and calculations made from the information received.

In operation of the present invention an anchor pipe 63, of suitablelength, is attached to the lower end of the armored casing l5. Thesurveying instrument I4 is mounted within the armored casing I5, and thetiming structure 45 set to determine the length of duration of theelectric circuit through the bulb when an exposure is to be made of thephotographic card 51. The core taking unit is then attached to thearmored casing l5 and is supported from a drill string J0 by theoperating rod l2. The entire structure is then lowered into the well asadditional lengths of drill stem are attached and until the anchor pipe63 encounters the bottom of the well bore and interrupts furtherlowering movement of the anchor pipe. The cores may then be taken bylowering the drill string the operating rod I2. This will force therelatively small piston |9 down within the bore I8 and since the bore l8and the bore 23 between piston l9 and 24 are filled with anincompressible liquid it will be seen that the downward movement of thepiston l9 will force the incompressible fluid into the cylinder 23 abovethe piston 24 to force the operating cams 3| downwardly and tosimultaneously force the core barrels 33 outwardly to impinge againstthe side wall of the Well bore and when continued outward radiallymovement of the core barrels 33 is brought about to cause the barrelseach to be filled with a core 64. When the drill string is lifted topick up the small plunger |9 the hydrostatic head of fiuid pressure willact against the large piston ring 24. In shallow wells mechanical meanscan be provided without departing from the spirit of this invention.Attention is directed to the fact that since the bores 34 of the barrels33 are undercut the cores 64 will be retained within the barrels andwill be extracted from the side walls as the barrels 33 move from theirinner positions as indicated in Fig. 5 to their outer positions asindicated in Fig. 6. At the time the core barrels 33 reach the outerends of their radial strokes-the blade 4| will pass between the contacts48 and 49. This will complete an electric circuit through conductors 46and 41, the battery 42, and the timing mechanism 45. This circuit willalso pass through the bulb 5|. After a predetermined interval, as set bythe timing device 45, the circuit will be broken and illumination of thebulb 5| discontinued. While the bulb 5| was illuminated it caused ashadow of the reticle ring 52 and the compass structure 62 to fall uponthe photographic card 51 so that a record could be made as indicated inFig. 7 of the drawings. The entire structure may then be withdrawn fromthe well and the photographic card and the cores removed and arranged sothat their combined date may be correlated to indicate the deviation ofthe hole, direction of deviation, the character of cores, and thedirection and declination of the strata of geological formation at thepoint and in the plane within which the cores were taken.

Attention is directed tothe fact that since the core taking members moveradially and freely through the side wallpf the device and the operatingcam is mounted for free movement with relation thereto, the longitudinalthrust imposed upon the housing and drill string will be relativelysmall andwill prevent the creation of undesirable strain on the variousparts. It will also be evident that the operation of. the core takingbarrels is not dependent upon any great amount of longitudinal strainwhich might be produced by lowering the entire weight of the drillstring onto the core taking apparatus, but that the amount of thrustnecessary for this purpose is only the amount of thrust required toforce the shaft l2 and its piston is downwardly within the cylinder I8to efiect the subsequent movement of. the cams 3|.

It will thus be seen that the structure here disclosed comprisesconvenient means and method whereby cores may be taken from the walls ofa well at any point in the length of a well bore, and that the exactcondition of the formation and the character of formation may bedetermined with reference to a plane which may be definitelyascertained.

While I have shown the preferred form of my invention, and the method ofpracticing the same, it will be understood that various changes in theapparatus and steps of the method may be made by those skilled in theart without departing from the spirit of the invention as claimed.

Having thus described my invention, what I claim and desire to secure byLetters Patent is:

1. A device for taking side wall cores, which comprises a core takingunit including means penetrating the side walls and extracting a core, awell surveying unit-associated therewith for recording the direction anddeviation of the well bore from the vertical, an anchor pipe forpositioning the structure at a desired depth in a well, means operablethrough the drill string for actuating the core taking unit to penetratethe side -wall of the well bore and to extract the core, and

an electrical circuit operable simultaneously with the core actuatingmeans for producing operation of the declination recording device.

2. A device for exploring a well bore, which comprises a core takingunit having means 'to move laterally of the well bore and extract a corefrom the side wall thereof, a supporting element upon which the unit ismounted and by which it is lowered into the well, actuating meanscontrolled by the supporting element for actuating the laterally movingcore extracting members, an anchor pipe for determining the positionwithin the well bore at which the core extracting members operate, and adeclination instrument operable simultaneously with the actuation of thecore extracting members for taking a reading of the direction and degreeof deviation of the well bore from the vertical at substantially thelevel within the well bore at which the core extracting members operate,a declination instrument adapted to take a reading of the direction anddegree of deviation of the well bore from the vertical at substantiallythe level at which the core is taken, and common cooperating meansactuated by the supporting element to operate 4. A device for exploringan oil well which' comprises a core taking unit, said unit including aplurality of radially movable core barrels to be forced into the sidewall of a well bore and'to extract cores therefrom, a supporting elementupon which said unit is supported and by which it is lowered into thewell, a dash-pot actuated by said supporting member whereby the corebarrels are radially advanced and retracted, said dash-pot limiting thedownward movement of the core taking unit, thus determining the point atwhich the core barrels will be projected into the wall of the well boreto obtain a core, and a well surveying unit operable simultaneously withthe operation of said core taking unit for making a record of thedirection and degree of deviation of the well bore at substantially thepoint at which the core taking unit is operated.

5. A device for exploring an oil well which comprises a core takingunit, said unit including a plurality of radially movable core barrelsto be forced into the side wall of a well bore and to extract corestherefrom, a supporting element upon which said unit is supported and bywhich it is lowered into the well, a dash-pot actuated by saidsupporting member whereby the core barrels are radially advanced andretracted, said dash-pot limiting the downward movement of the coretaking unit, thus determining the point at which the core barrels willbe projected into the wall of the Well bore to obtain a core, a wellsurveying unit operable simultaneously with the operation of said coretaking unit for making a record of the direction and degree of.deviation of the well bore at substantially the point at which the coretaking unit is operated, and

means efi'ected by the operation of the core taking unit tosimultaneously initiate the operation of the surveying unit.

6. A core taking device comprising a main barrel adapted to be loweredinto a well, a plurality of radially moving core barrels slidablymounted in the main barrel, and means longitudinally movable within themain barrel to advance and retract said core barrels to and from theircore taking positions, said means including cam members acting toadvance and retract the core barrels, and a piston connected therewith,a cylinder within which said piston reciprocates, a second cylinder incommunication therewith, a piston within said cylinder, and meansactuated from the top of the Well for moving said last named piston.

7. In combination with a drill string, a core taking device comprising atubular housing having lateral openings therein, walls providing upperand lower communicating cylinders in said housing adapted to contain anincompressible fluid, a primary piston operable in the upper cylinderand having a rod connected to the lower end of said drill string, asecondary piston operable in said lower cylinder and having a rodextending downwardly therefrom, a plurality of core barrels slidablymounted in said lateral openings, a cam member connected to said secondmentioned piston rod and having a plurality of radially disposed bladesadapted to advance said core barrels into core taking positions and forretracting said barrels within said housing, and said drill string beingadapted for reciprocation to cause displacement of the incompressiblefluid from one cylinder to another whereby said blades will advance andretract said core barrels relative to said housing.

8. In combination with a drill string, a core taking device comprising atubular housing associated with said drill string, walls providing upperand lower cylinders in said housing and a bore communicating betweensaid cylinders, said cylinders being adapted to contain anincompressible fluid, a primary piston operable in said upper cylinderand connected to said drill string, a secondary piston operable in saidlower cylinder and having a rod extending downwardly therefrom, wallsproviding a plurality of lateral openings in said housing, a pluralityof core barrels slidably mounted in said openings, a cam.

member connected to said second mentioned piston rod and having aplurality of radially disposed blades adapted for engagement with saidcore barrels, and means for causing displacement of fluid from onecylinder to the other so as to advance and retract said core barrelsrelative to said housing.

9. A device for exploring a well bore which comprises a supportingelement adapted to be lowered into a well, a core taking unit, saidsupporting element supporting the core taking unit on the lower endthereof, operating means for said core taking unit comprising a dash-potstructure interposed between the supporting element and the core takingunit, said dash-pot means being actuated by the manipulation of thesupporting element, a well surveying instrument associated with the coretaking means, and cooperating means consisting of an electrical circuitbetween the core taking means and the Well surveying instrument toactuate the well surveying instrument simultaneously with the operationof the core taking unit.

10. A device for exploring a well bore which comprises a supportingelement adapted to be lowered into a well, a core taking unit, saidsupporting element supporting the core taking unit on the lower endthereof, a dash-pot interposed between the supporting element and thecore taking unit, said dash-pot being operable by manipulation of thesupporting element, a well surveying instrument associated with the coretaking unit, said well surveying instrument adapted to take a singleexposure of known orientation, and cooperating means comprising anelectrical circuit associated with the core taking unit and the wellsurveying instrument to actuate the well surveying instrumentsimultaneously with the operation of the core taking means.

11. A device for exploring a well bore which comprises a supportingelement adapted to be lowered into a well, a core taking unit, saidsupporting element supporting said core taking unit on the lower endthereof, a dash-pot interposed between the core taking unit and thesupporting element, said dash-pot unit being actuated by themanuipulation of the supporting element to operate the core taking unit,a well surveying instrument associated with the core taking unit, anelectrical circuit associated with the core taking unit and the wellsurveying instrument, said well surveying instrument adapted to take asingle exposure on a photographic plate, said exposure being of knownorientation and inclination, and means actuated by the core

